Keyboards are known for use with standard-type personal computers. A standard-type personal computer, as referred to in the present specification, refers to one which includes a central processing unit (CPU), most commonly an Intel 80X86 type, Motorola 680X0 type, a Power PC type, RISC (MIPS, SPARC, etc.) or other known processors. This processor communicates with a user feedback device, such as a display driver, which is generally a driver for a video display or a liquid crystal display. The display driver, in turn, causes an associated display to present a visual image to a user. The display may be a modular display or a display intimately associated with the computer. The processor may also communicate with an audio driver, which produces sound through an audio transducer. In some instances, an audio transducer may be the only user feedback mechanism present.
A standard-type personal computer also has a non-volatile mass storage system for storing a predetermined program for the CPU. This mass storage system may be ROM, EPROM, EEPROM, Flash memory, FRAM, battery-backed RAM, magnetic media, e.g., hard disk and/or floppy disk, optical media, e.g., CD-ROM, R-CD-ROM, magnetooptical media, or other data storage systems known in the art. The program stored in the mass storage system includes the basic input/output system (BIOS), and optionally a disk operating system (DOS) and application software. Application software may also be available by telecommunication link to a remote mass storage system.
Standard-type personal computers also include a human input device, such as a keyboard, joystick, mouse, voice and/or other type of device to receive an input from a human to be interpreted by the CPU as data to control its operation. Generally, manual input devices for computers comprise keyboards having a plurality of keys, arranged in a tight matrix, having associated linguistic symbols. These symbols, are generally letters and numbers, and as taught in the art, a keyboard should include access to a complete standard alphabet of symbols, plus functional symbols. Thus, the art teaches keyboards for standard-type personal computers having at least 28 keys, e.g. 26 letters, "space" and "enter", and possibly also punctuation, 10 number keys, 12 function keys, cursor movement keys, program control keys, etc. Further, these keyboards are generally arranged to approximate the spacing of adult fingers, with close gaps between keys sufficient to allow clearance without substantial interference. Often keyboards will have intelligence to convert key depressions to codes which are communicated to the CPU through a serial communication port.
A known device, the "Comfy Keyboard", provides a limited number of keys in a device which interfaces to a standard IBM-PC compatible computer through a Centronics-type printer port. This device requires special software loaded into the computer to determine key presses, and further operates only with custom written software to make use of the input. This custom software may be designed to ignore input from the standard keyboard which is simultaneously attached to the computer. The keys on the "Comfy Keyboard" are spaced apart, and the device intended for use by children. This device is not designed to, nor will it interface with a standard keyboard port.
"Programmable chip adds flexibility to input devices", Electronic Products, December, 1993, page 43-44, describes a semiconductor device, "Pilot EZ1000" by Rosetta Technologies, Inc., West Vancouver, B.C., which allows a serial input device, such as a standard IBM PC compatible personal computer keyboard, to be daisy chained with an additional input device with complex functionality. This device stores a configuration in a memory, such as a 93C46 1-Kbit serial EEPROM, and is therefore reconfigurable and programmable. This device allows separate press and release codes for up to eight inputs, and can pass codes unmodified or modified from the standard keyboard to the computer. This device is promoted for use embedded in input devices like digitizers and joysticks, as well as game controls. Separate function key devices, having a separate housing, are also known.
Computer products of Apple Computer Co., Cupertino, Calif., generally communicate with keyboards, mice, trackballs, and other input devices through the "Apple Desktop Bus" or ADB, which provides a daisy chainable serial connection for a number of devices. A number of keyboard variants are available for the ADB, which are generally suited for adult use.
The U.S. Pat. No. 5,250,930 to Yoshida et al. relates to a keyboard for a self-contained computer. The keyboard comprises a membrane keypad and a soft rubber dome keypad. The membrane keypad includes a 7.times.10 rectangular array of sensing areas under a graphic overlay. This system thus provides a high density input array with a large number of pressure sensitive areas. While apparently intended for use by children, the ergonomics are not optimized to allow young children or children with undeveloped coordination or limited capabilities to easily interact with the computer.
Auxiliary numeric keypads are also known for use with standard-type personal computers, as are programmable "function keyboards" having an array of one or two rows of keys, closely spaced, which may be programmed to add complex functionality (macros) to supplement the available functionality of a standard alphanumeric keyboard. Generally, these devices do not share input circuitry in the computer with the standard keyboard if they do not share the same housing, i.e., signals travel to the computer through separate ports.
Some time in 1994 there appeared on market a "Game Star.TM. Game Controller" manufactured by DynaPoint, Inc. of Fremont, Calif. This device has a cursor pointing device and six buttons arranged in a 2.times.3 array. It plugs directly into the keyboard connector of a personal computer while permitting simultaneous use of the for PC keyboard. The Game Star.TM. Game Controller is programmable in the sense that all of the game control buttons are configurable and the configurations can be saved and retrieved as templates. However, this device is intended for special use with Nintendo and Sega type games, not as a general purpose input device to provide symbolic data for use by the computer software.